package dk.thoerup.traininfoservice;

import java.util.Timer;
import java.util.TimerTask;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;


public class StatisticsListener implements ServletContextListener {

	Timer timer = null;
	int update_interval;

    public void contextInitialized(ServletContextEvent sce) {
    	
    	update_interval = getUpdateInterval( sce.getServletContext() );
    	if ( update_interval > 0 ) {
	        timer =  new Timer();
	        
	        TimerTask statsUpdate = new TimerTask() {
				@Override
				public void run() {
					Statistics.getInstance().saveStats();
				}
	        };
	        
	        timer.schedule(statsUpdate, 0, update_interval);
    	}
    }


    public void contextDestroyed(ServletContextEvent sce) {
    	if ( update_interval > 0 ) {
    		timer.cancel();
    	}
    }

    private int getUpdateInterval(ServletContext cntx) {
    	int interval = 0;
    	try {
    		String intervalStr = cntx.getInitParameter("stats_interval");
    		interval = Integer.parseInt(intervalStr);
    	} catch (Exception e) {}
    	
    	return interval;
    }
}